1. Field of the Invention
The present invention relates generally to hammers, more particularly to hammers having a nail placer, and most specifically to hammers having a nail placer for driven type fasteners.
2. General Background
Lengths of metal channels, commonly known as xe2x80x98tracksxe2x80x99 as used in construction, are typically fastened to concrete substrates with the use of driven type fastening pins possessing an outer collar that is shorter than the central steel member and typically possesses a radially symmetric configuration, most typically or a longitudinal set of exterior radial splines of substantially uniform diameter but also characterized by a shoulder at an upper end with an enlarged diameter. The central steel member has an outward flange or head at the top end presenting a flat circular top impact surface. The maximum diameter of the collar is slightly greater than the diameter of the impact surface of the head. This structure is considered to be ideally suited to use in powder actuated and fuel cell type guns as the radially symmetric collar facilitates feeding or guiding of the fastening pin. Use of radial ribs on the most typical type of fastener, as opposed to a solid cylindrical shape, and provision of the shoulder with radially spaced small outward protrusions or buttons, are both intended to avoid jamming in powder actuated or fuel cell type guns.
Building construction workers typically use powder actuated or fuel cell type guns specifically for driving fastening pins through metal tracks and into concrete substrates typically forming walls or floors and use other hand tools such as a conventional hammer and or drywall hatchet in constructing interior walls typically braced at ends to poured concrete slab walls by the fastened metal tracks. Conventional, clawed, hammers typically used by workers in building construction are considered to be well known. The head has a bifurcated claw end opposed to a generally cylindrical end presenting the substantially flat, circular, impact surface applied to the heads of conventional nails for the purpose of fastening wood members. The claw is used to pry a poorly hammered nail from the wood. In a heavier version with a comparatively shallow claw the same is generally known as a wrecking hammer for self explanatory purposes.
It considered that hammers of other configurations are known including tack hammers for tacking or light work, ball peen hammers for metal work, et cetera. Most pertinently to the problem addressed herein a variety of hammers having nail placers are known. A nail placer allows one to place a nail with the hammer as opposed to holding the nail with one hand against a surface and directing the blow of the hammer toward the same. A hammer with a nail placer allows one to start the nail without placing the fingers of a hand in the path of the impact surface of the hammer head. The benefit derived is elimination of a potential hazard to the fingers of the hand holding the nail.
Track fasteners are generally too short and of too awkward a shape to be easily held by one""s fingers, particularly at the bottom of a relatively narrow channel which prohibits flattening of the hand. The impact necessary to start a track fastener in metal track is much greater than that necessary to start a nail in the wood used in construction and placing a track fastener with one""s fingers for starting the same with the blow of a conventional hammer is considered to impose an unacceptably high level of hazard upon the task.
A hammer that might be used to start a track fastening pin of the kind described therefor necessarily must possess a nail placer suitable to the specific shape and configuration of the typical track fastening pin as described in some detail above. And the prior art considered pertinent to the present invention is hence defined by this characteristic coincident with the language used by the U.S. Patent Office Classification System found in the xe2x80x98Field of the Inventionxe2x80x99 above.
The presumed brothers Thurston disclose a hammer with the shaft connected to an end of a heavy, longitudinally tapered, head having a blind cavity, of cylindrical, oblong, square, or of triangular shape, centrally located and open to the impact face on the opposed, thicker, end of the head. The impact face is necessarily convex, sloping backward in a radially outward direction from the central cavity, in order to avoid deformation of the teeth on the saw blade adjacent to the tooth avoided by the blind cavity during straightening of the blade with the hammer.
Pies discloses a xe2x80x98shingle gage attachment for hammersxe2x80x99 having an externally threaded extension with a distal flange threaded into a tapped bore through an end of the hammer head connected to the shaft bore and opposed to the end having the impact face. The threaded extension has a xe2x80x98gauging abutment 16xe2x80x99 or flange on its end and is fixed by means of a lock nut at any desired extension thereby providing a gauge convenient to someone laying roof shingles and obviating the need for a chalk line for each successive row of shingles.
Miller discloses a claw hammer having a deep smooth walled cylindrical blind cavity open to the back, claw equipped, end of the head having an arcuate thin strip of steel disposed therein shaped to exert downward pressure upon the length of a nail inserted in the cavity thereby retaining the same therein. A tapered V shaped groove centered at the bottom of the open cavity centers the length of a nail disposed therein. The steel strip is fastened to the blind end of the cavity with a semi-spherical head bolt screwed into a tapped aperture behind the blind end which shape ensures, together with the centered groove, that the center of the impact surface of the nail head is contacted during the blow using the bolt head as a striking point for delivery of impact.
Pearson discloses a conventional claw hammer having a cylindrical magnetic insert made of high carbon hardened steel heat treated prior to magnetization press fitted into a cup shaped sleeve or xe2x80x98magnetic shield thimble 6xe2x80x99 in turn press fitted into a cylindrical blind cavity formed in the impact face of the head of the hammer thereby xe2x80x9cpresenting a flush face which may then perform the combined functions of magnetic pick-up and driving over long periods of time without impairing the function of the magnet.xe2x80x9d (Abstract)
Chung discloses a xe2x80x98measuring hammerxe2x80x99 having a scale incised along the steel shank integral to the head above the rubber sleeve handle further possessing a round cavity, or nail holding aperture 16 which is adapted to receive a nailxe2x80x9d open to the surface opposed to the end with the impact surface, below the base of the claw, and disposed to retain the head of a common nail extending backward through the wedge shaped gap between the bifurcated claws while starting a nail.
Note
The xe2x80x98nail holding aperturexe2x80x99 co-operating with the bifurcated claws in xe2x80x98starting a nailxe2x80x99 in Chung is known in many variations in the prior art which is otherwise mainly characterized by attachments or slots on the side of the hammer head for starting a nail with the hammer in a forward position, as indicated by the references cited.
The references cited represent all the prior art found disclosing a hammer structure possessing a cylindrical blind cavity open to an end of the head of the hammer. While the purpose of the cavity varies, still, regardless of the purpose, no reference was found in the pertinent prior art which disclosed use of a smooth walled cylindrical blind cavity of sufficient depth to hold a collared type track fastening pin concentrically therein centrally located upon a distal face of a double ended hammer head. The particular problem addressed by the present invention, safely starting a track fastening pin with a simple hammer that can also be used for other conventional purposes, is wholly absent from the pertinent prior art and the references cited herein are considered to be the closest structure found necessary for address of this specific problem as well as the references considered to be closest in function.
It is considered that powder actuated and fuel cell type guns are: heavy, expensive, prone to incur significant downtime, and are dedicated to a particular fastening operation; all in contrast to a conventional hammer. And it is considered that while hammers of a wide range of configurations aside from conventional claw hammers are known that have a nail placer, all are useful only for conventional nails and none are suitable for starting a collared type track fastener with a hammer safely. And, of course, powered guns dedicated to starting and driving collared type track fasteners safely are useless with conventional nails. A need is hence recognized for a hammer which can be used in a conventional manner with nails that can also safely start and drive collared typed track fasteners.
The encompassing object of the present invention is a tool suited to both: starting collared type track fasteners without having to hold the fastener with one""s fingers; and conventional use as a hammer in driving this and other fasteners including nails.
A first ancillary object of the present invention is a tool suited to starting collared typed track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that is less expensive than a powered track gun.
A second ancillary object of the present invention is a tool suited to starting collared type track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that is less massive than a powered track gun.
A third ancillary object of the present invention is a tool suited to starting collared type track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that is simple, durable, and hence not subject to lapses in operation by reason of mechanical jamming and other problems.
A first auxiliary object of the present invention is a tool suited to starting collared typed track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that is basically one piece and possesses no moving components.
A second auxiliary object of the present invention is a tool suited to starting collared type track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that is easily used in comparatively tight places.
Other auxiliary objects of the present invention include a tool suited to starting collared type track fasteners without fingers holding the fastener and to conventional use as a hammer in driving these and other fasteners that enables precision, speed, and ease in operation.
In achievement of the above stated objectives it is suggested that a hand held hammer be provided having both a conventional striking structure at one end of the head, to enable conventional use in driving both collared type track fasteners and other types of driven fasteners including nails, and an appropriately configured structure on the opposed end of the head for starting collared track fasteners. After starting a track fastener with the opposed end it is suggested that the hammer be rotated one hundred eighty degrees and driven with the conventional striking structure on the other end of the head. It is suggested that a cylindrical blind cavity open to the distal end of the head suited to starting a collared track fastener possess a diameter and depth appropriate to stable disposition of the same therein. It is specifically suggested that the diameter of the cylindrical blind cavity be approximately equal to the maximum diameter of the collar and therefor slightly larger than the diameter of the flanged head of the central steel pin of a collared track fastener. And it is specifically suggested that the depth of the cylindrical blind cavity be at least sufficient to admit insertion of both the head and a portion of the collar of the track fastener sufficient to provide a stable disposition.
Together these two physical aspects ensure stability in both the placement of the track fastener into the cylindrical blind cavity and starting the same with a blow of the hammer directing the point of the central fastening pin against the desired surface. The fastening pin point is easily driven through the track surface with one blow starting the track fastener. A collared track fastener is held in placed position by contact of radially balanced contact surfaces against the interior wall of the cylindrical blind cavity which must simply have a depth sufficient to allow insertion of a portion of the maximum diameter of the collar therein to ensure against accidental displacement.
It is suggested that the exterior configuration about the cylindrical blind cavity be radially uniform and possess a slight taper inward toward the distal face upon which the cavity opens. This configuration places nearly all the mass of this striking end, and hence the hammer head, behind the bottom of the blind cavity and hence behind the head of the fastening pin of a track fastener disposed therein. This configuration also minimizes the area presented about said cavity opening thereby facilitating greater accuracy in starting the track fastener as restrictions imposed by desired physical location, for example at the end of a narrow channel track, are obviated.
With the centerline of the cylindrical blind cavity coincident with the centerline of an opposed conventionally configured striking end, the configuration of the head provides for an intuitive feel in use of either end of the head of the hammer in starting and then driving home the fastening pin. Symmetry about a medial plane through the centerline is also desired for ensuring an intuitive feel in use in either direction. It is noted, however, that the relative mass, and hence weight, upon either end of the head is not important in this regard and the striking end is preferably of lesser size than that of the opposed, solid, conventional striking head.
It is suggested, moreover, that the head be manufactured in one piece, preferably with conventional forging or casting techniques. An insert for the forging die is necessary for the blind cavity as well as a central head through cavity for the handle if a traditional hammer construction is utilized having a spike wedged into the top of the handle. Alternatively the handle can be forged in one piece with the head, brazed within a blind cavity of the head, or fixed by any other suitable, including threaded, means. It is suggested, regardless of specific manufacturing means, that a bifurcated claw be provided upon the top of the hammer head. This location places the fulcrum involved proximate the longitudinal axis of the handle thereby providing optimal leverage.
Other objects and advantages may be discerned in review of the detailed description following; especially if made with reference to the drawings attached hereto and briefly described immediately below.